In a digital microwave communications system, a 1+1 hot standby manner is usually selected to improve communication reliability. That is, for two devices having a same working frequency, only one device is working; when the only working device fails, a switchover to the other standby device is performed immediately, thereby ensuring communication reliability.
In another aspect, in a digital microwave communications system, a 2+0 manner or cross polarization interference cancellation (“XPIC” for short) manner is usually selected to improve a transmission capacity. The 2+0 manner refers to that two devices are working at the same time and have different working frequencies, and therefore, a transmission capacity of a system can be doubled in comparison with a single device or single channel. The XPIC manner, namely a polarization diversity manner, refers to that two devices are working at the same time and have a same working frequency, but the two devices use a manner of reusing a co-channel or interleaved additional channel cross-polarization frequency to improve spectrum utilization, thereby enabling a transmission capacity of a system to be doubled.
However, currently outdoor units (“ODU”s for short) are all single-channel. A system needs to have two ODUs to implement a 1+1 hot standby manner, a 2+0 manner, or an XPIC manner. Moreover, in an application of the 2+0 manner, an external coupler needs to be added to the system; and in an application of the XPIC manner, an external orthomode transducer (“OMT” for short) needs to be added to the system. Therefore, in an actual application, not only costs of devices are increased, but also installation space of various devices configured externally is considerably increased, thereby increasing device installation complexity, further increasing costs, and meanwhile leading to an inflexible device application.